HOW ARE THE DEALS GENERATED?

As most of you will know, hands in major championships have been computer generated for a very long time. Since 2000, this has always been done by the program BigDeal, which I wrote. Sources and documentation of BigDeal have been available through http://www.xs4all.nl/~sater since then. Nobody has yet found an error in the program and by now it should be regarded as safe to use.

However, and that is a big however, even though the program is OK it could still be misused. A real blatant misuse would be if the Tournament Organizer (TO for short) were to smuggle an interesting hand into an otherwise normal set. A little less blatant would be if the TO were to create a set of hands, look at it, and for whatever reason decide to make a new one. There are also rumours every now and then that if three sessions are played in a day, the TO picks the most interesting set for the evening session. Clearly all of this is very bad and should not happen.

There is only one good way to use BigDeal, or any other dealing program. Generate the hands, duplicate them and play them. Never even look at the hands. The players should be the first to see them. And I am pretty much convinced that – at least at WBF and EBL events – this is what happens. There are, however, always rumours, and until now the TO has had no defence against them. He can only say he is honest, but cannot prove it.

Some years ago, I developed a method that will allow the players to check the honesty of the TO after the event. From the player’s perspective it looks as follows:

Before the tournament the TO publishes a short file containing information about the various phases of the tournament, and the board numbers per session. This has been done by the Organisation for this tournament (see the web site www.bridge-madeira.com or the bulletin).

This file also contains a big number, called a checksum

Interested players can keep a copy of this file until after the tournament

After the tournament the TO publishes this file again, with a slight modification, and another file containing all the numbers used to generate all the hands of the sessions

Interested players can now run the same software used by the TO to generate all the hands of the tournament and compare it to the hands they played. They should all be the same.

There is a lot of technology involved in this software, and if you are not into computer science and/or mathematics most of it will probably not be comprehensible to you. If, however, you are, or know someone who is, the detailed documentation and the software is here: http://www.xs4all.nl/~sater/SquareDeal.zip, currently containing exactly the software used in this tournament. Later it will be updated.

It is important to realise that the use of this software basically takes away all the freedom of the TO. He must generate the predetermined hands and has no liberty left whatsoever to change them. In WBF and EBL tournaments this is done by Maurizio di Sacco; here it is done by José Júlio Curado. Both are very keen to have this freedom taken away. All this means that if you use this method, there is an answer to players who doubt whether the hands were dealt honestly. From now on you can just ask them to generate the hands themselves. If they find a difference it is time to investigate.

Also, hands generated in this way are not distinguishable from hands made the “old-fashioned” way. The king of clubs will be singleton just as often.

I am currently employed in this tournament as a TD. Should anyone want a more technical update or discussion feel free to talk to me.

Come and enjoy good bridge in the setting of our beautiful island. We look forward to welcoming you for the main programme of Open Pairs and Teams (6th-11th November 2018), and for our side events and social programme.